Generate a random band of the electromagnetic spectrum, from radio waves to gamma rays. Filter by region to explore or study how the spectrum is organized.
The electromagnetic spectrum is the full range of electromagnetic radiation ordered by wavelength, from radio waves metres long to gamma rays smaller than an atomic nucleus. It is one phenomenon throughout -- light -- and the named bands mark how we produce and detect each stretch, not any physical boundary. Visible light occupies a sliver from roughly 380 to 750 nanometres. Wavelength dictates use: radio passes through walls, X-rays through soft tissue, and microwaves match the frequencies water absorbs.
This generator draws from a curated list of 34 frequencies and bands across the electromagnetic spectrum's seven regions -- Radio, Microwave, Infrared, Visible Light, Ultraviolet, X-ray, and Gamma Ray -- from AM radio's kilohertz to gamma rays' exahertz, each explained in plain language.
Every result here is drawn using crypto.getRandomValues() -- the Web Crypto API's cryptographically secure randomness -- instead of Math.random(), so it's genuinely unpredictable, not just statistically random. Learn more.
Physics students use it to build intuition for the spectrum's scale, since the jump from radio to gamma spans some eighteen orders of magnitude. Teachers use it for quick lesson prompts, and the curious use it to learn what actually operates at each frequency -- Wi-Fi, microwave ovens, sunburn.
Generate draws one frequency at random using the site's cryptographically secure randomness, guaranteed not to repeat whatever result is currently showing in single-result mode. Each single result describes what lives at that frequency and why it matters, and the Region filter narrows the pool to spectrum bands you're studying.
A sample of what this generator can draw, spread evenly across the full list:
They're inverses -- frequency times wavelength equals the speed of light, so higher frequency always means shorter wavelength. Radio waves stretch meters to kilometers; gamma rays are smaller than an atomic nucleus.
Ionizing radiation -- far ultraviolet, X-rays, and gamma rays -- carries enough energy per photon to damage molecules. Radio through visible light is non-ionizing; intensity, not frequency, is the concern there.
Band boundaries are conventions, not physics -- the spectrum is continuous, and named bands like microwave and radio blur into each other at the edges. The descriptions flag where definitions vary.
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